Interlocking masonry wall block

ABSTRACT

The present invention relates to an interlocking masonry wall block having an open core and spaced projections that enable stacked blocks to be interlocked, setback and staggered to form a stable gravity-type retaining wall that is particularly suited for landscaping applications. The open core extends completely through the block from top to bottom. The block is formed by front, rear and opposed side walls, each having parallel inside and outside surfaces. One projection extends from the lower surface of each side wall. The front of each projection is forward the inside surface of the front wall to provide the setback when stacked on other like-shaped blocks. Each block is stacked in a staggered manner atop two other blocks. One projection of each block is received by the open core of one of the two lower blocks. The projections abut the inside surface of the front wall of the lower blocks to interlock the blocks together. The block has a preferably trapezoidal shape with a wider front wall to help accommodate the formation of serpentine walls. The block can be used to make serpentine walls with straight and curved portions with a relatively constant pitch.

TECHNICAL FIELD OF THE INVENTION

[0001] This invention relates to a masonry block for stacking on other like-shaped blocks in a staggered, interlocking and offset manner to form a gravity-type retaining wall that is particularly suited for integrating into a variety of landscape settings.

BACKGROUND OF THE INVENTION

[0002] A variety of masonry block designs have been developed for building gravity-type retaining walls that depend on the weight of the blocks for their stability. Versatile block designs should take several factors into consideration. For walls three feet in height or less, the blocks should form a wall structure that can withstand the pressure of the earth behind the wall. The footprint of the block should be large enough to accommodate soils with relatively low bearing pressures so that the wall will not tilt or sink during use. The setback and height of the block should be such that the combined pressure of the earth and the weight of the wall fall within the footprint of the lowest course of blocks. The block design should also take into account the shape of the blocks, as well as the strength, density and durability of the material forming the block.

[0003] Retaining wall block designs require a mechanism for securing the blocks together to produce a stable wall structure. While the friction between the relatively rough surfaces of stacked blocks can help keep the wall together, this friction is not sufficient in many retaining wall applications. To increase stability, some blocks are designed to be mortared or otherwise adhered together to produce a rigid wall structure. Unfortunately, such retaining walls are prone to cracking due to settling, frost, water buildup behind the wall and earthquakes, as well as the normal use of the wall by people and animals that walk, stand, lean or sit on the wall.

[0004] Other retaining wall block designs incorporate fasteners such as rods, pins or keys to hold and clamp the blocks together. Examples of such block designs are shown in U.S. Pat. Nos. 4,914,876 to Forsberg, 3,390,502 to Carroll, and 4,909,010 to Gravier, the disclosures of which are incorporated by reference herein. A significant problem with these block designs is the expense of the extra components and increased installation costs. These designs can also suffer from unsightly cracks that tend to form in these types of walls.

[0005] Interlocking wall block designs have been developed to overcome the problems associated with the blocks that form rigid retaining wall structures. Interlocking block designs typically have one or more integral projections extending from the upper or lower surface of the block. When stacked, the projection of one block abuts against a surface of another block to help hold the blocks together. The projections also provide a mechanism for offsetting stacked blocks. This offset or setback helps produce a more stable retaining wall that leans into the earth or hill behind the wall to resist the pressure exerted by the earth or hill on the wall. Individual blocks do not need to be rigidly secured by mortar, adhesive, rods, pins or keys, so that the wall is free to flex and accommodate movements in the wall caused by settling, frost, water buildup, earthquakes and normal use. Blocks for retaining walls of this type are described in U.S. Pat. Nos. 5,827,015 to Woolford, 2,313,363 to Schmitt, and 4,565,043 to Mazzarese, the disclosures of which are incorporated by reference herein.

[0006] One problem with conventional interlocking masonry wall blocks is that the thickness of the integral projection is directly related to the amount of setback desired for each course of blocks. A retaining wall application requiring a half-inch setback per course requires blocks with half-inch thick projections. Yet, thin projections are structurally weak and prone to chipping and cracking. While the height of the block can be increased to increase the thickness of its setback, this results in a heavier block that is more difficult to handle. In addition, tall blocks also do not lend themselves to landscaping gradually sloping terrain. Large portions of the block stick out above ground level before a step down at the end of a row or course of blocks can occur. This produces an unsightly wall and results in a waste of material.

[0007] Another problem with conventional interlocking masonry wall blocks is that the integral projection is located along the rear or front edge of the block. As noted above, the setback projection is frequently only a half-inch thick when the blocks are sized for easy handling. Yet, these relatively thin and weak projections are located where they are easily damaged if dropped, improperly stacked or otherwise mishandled. In addition, rear projections are in direct contact with the wetness and acidity of the earth during use, which can cause the projection to deteriorate, weaken and fail over time. Front projections extend upwardly and can collect water between them and the upper course of blocks, which can freeze and crack the projection.

[0008] A further problem with conventional interlocking masonry wall blocks is that the integral projections are relatively short in height to reduce the possibility of chipping and cracking. Although the short projections may be less likely to crack, they do not provide a sufficiently tall abutment to easily and consistently align the block over a lower course of blocks. During construction of a wall, workers have a tendency to leave a gap between the projection and the lower course of blocks or allow the projection to ride-up onto the upper surface of the lower block. These misalignments are not easily detected given the thinness of the projection and its relatively small height. This is especially so for blocks with rear projections that extend down from the lower surface of the block, because the workers are not able to easily see that the blocks are properly aligned. Misalignments can be even more difficult to notice in construction settings where dirt, gravel and other debris are present, and may compact against the setback projection or get on the upper or lower surfaces of the blocks.

[0009] A still further problem with conventional interlocking masonry wall blocks is that they have limited ability to produce serpentine walls with straight, concave and convex portions. The integral projections are sized and shaped to fit into grooves of lower blocks so that the stacked blocks must be oriented a particular way. If a curve is possible, the radius of the curve is constant, so that a true serpentine wall with curves that gradually increase or decrease in radius are not possible. These limitations of conventional block designs prevent the wall from being integrated into the natural contours of the landscape and thus impede the aesthetic value of the wall.

[0010] A still further problem with conventional interlocking masonry wall blocks is that the integral projections do not ensure an even amount of setback for straight and curved portions of the wall. For example, a block with a flange along its front or rear edge produces a wall with discontinuities in the amount of setback between adjacent block as shown in FIG. 14. In addition, the pitch of the wall is also greater in both the concave and convex curved portions of the wall than in the straight portions as shown in FIGS. 14 and 16. This increasing setback and pitch occurs even though a retaining wall may need to be stronger and require more setback in straight portions of the wall than in curved portions.

[0011] A still further problem with conventional interlocking masonry wall blocks is that the blocks require a fixed amount of lateral offset to the right or left of the lower blocks on which they rest. Yet, obstructions at the location where the wall is to be built or the addition of drain pipes in the wall do not always permit each block to be offset a constant amount throughout the entire wall. A block in one course may need to be laterally offset two or three inches to the right or left from the blocks beneath it, and another block in the same or a different course may need to be laterally offset four or five inches from the blocks beneath it. Yet, many interlocking block designs do not allow sufficient flexibility to offset the blocks as needed to accommodate various obstacles or drain pipes. This inflexibility can complicate construction or renders the block unusable for some retaining wall applications.

[0012] A still further problem with conventional interlocking masonry wall blocks is that the integral projection does not provide sufficient resistance to lateral side-to-side movement of the block. Side-to-side movement is only resisted by adjacent blocks in the same course or tier. The side walls of these adjacent blocks abut each other to prevent side-to-side movement. However, should one block in a given course shift or move out of abutting alignment with one of its adjacent blocks, then each of the blocks in that row would be susceptible to shifting as well. Moreover, the blocks that form an end of the wall are not restrained from lateral movement away from its sole adjacent block and could be knocked off the wall altogether.

[0013] A still further problem with conventional interlocking masonry wall blocks is that several different block shapes must be combined to form the straight and curved sections of a serpentine wall. The need for multiple block designs result in increased manufacturing, inventory, shipping and construction costs. The multiple block designs also result in more complicated serpentine wall designs that are not easily integrated to the shape of a specific and unique landscape setting.

[0014] A still further problem with conventional interlocking masonry wall blocks is that they are heavy and difficult to handle. The blocks are typically solid throughout. The openings tend to be small and do not significantly reduce the weight of the block. The excessive weight is compounded by the fact that the block must be tall enough to provide a setback projection or flange that is sufficiently thick to withstand cracking and chipping during transport, construction and use.

[0015] The present invention is intended to solve these and other problems.

BRIEF DESCRIPTION OF THE INVENTION

[0016] The present invention relates to an interlocking masonry wall block having an open core and spaced projections that enable stacked blocks to be interlocked, setback and staggered to form a stable gravity-type retaining wall that is particularly suited for landscaping applications. The open core extends completely through the block from top to bottom. The block is formed by front, rear and opposed side walls, each having parallel inside and outside surfaces. One projection extends from the lower surface of each side wall. The front of each projection is forward the inside surface of the front wall to provide the setback when stacked on other like-shaped blocks. Each block is stacked in a staggered manner atop two other blocks. One projection of each block is received by the open core of one of the two lower blocks. The projections abut the inside surface of the front wall of the lower blocks to interlock the blocks together. The block has a preferably trapezoidal shape with a wider front wall to help accommodate the formation of serpentine walls while maintaining a consistent front wall appearance. The block can be used to make serpentine walls with straight and curved portions with a relatively constant pitch.

[0017] One advantage of the present interlocking masonry wall block is that the thickness of the integral projections is not related to the desired amount of setback for each course of blocks. A retaining wall application requiring a half-inch setback per course can have projections that are one or two inches thick. These thicker projections are more structurally sound and not prone to chipping and cracking. The block can be relatively short in height to produce a block that is light weight and easy to handle.

[0018] Another advantage of the present interlocking masonry wall block is that the block can be kept relatively short so that it can be more easily integrated into gradually sloping terrain. The smaller height allows more frequent steps to be incorporated into a particular wall design so the blocks do not rise up above ground level a great deal. This produces a more aesthetically pleasing wall that fits and blends into the natural terrain. The blocks also make more efficient use of material.

[0019] A further advantage of the present interlocking masonry wall block is that the integral projections are located away from the rear and front edges of the block. By locating the projections in this manner, they are less likely to be damaged if the block is dropped or bumped during transport. During shipping, the bottom layer of blocks are inverted to lay flat on the floor, truck bed or shipping pallet. The projections of one block fit into the openings of the other blocks. The various columns and rows of block are arranged flush against adjacent columns and rows of blocks to provide a solid mass of blocks. The projections are also protected by the lower blocks during use so that they are not exposed to the earth and air. This keeps the projections dry and away from the acidity of the earth, which improves the life expectancy of the block and retaining wall formed by the blocks.

[0020] A still further advantage of the present interlocking masonry wall block is that the integral projections are relatively thick and relatively tall. As stated above, the projections can be relatively thick or long because they are not dependent on the desired setback. This increased thickness enables the projections to have an increased height without compromising their structural strength. The projections provide a sufficiently tall abutment to easily and consistently align the block over the lower course of blocks. This reduces the amount of misaligned blocks, and improves the strength and aesthetic uniformity of the retaining wall.

[0021] A still further advantage of the present interlocking masonry wall block is that they produce serpentine walls with varying convex and concave shaped portions. The size and shape of the open cores allow the smaller, spaced projections to fit into the open cores of the blocks of the lower course. Adjacent blocks can be oriented to form a continuous wall with curves and straight portions that gradually increase or decrease in radius.

[0022] A still further advantage of the present interlocking masonry wall block is that the integral projections produce a relatively uniform amount of setback for straight and curved portions of the wall. Even though the setback increases slightly in concave curved portions of the wall and decreases slightly in convex portions of the wall, this change in setback occurs evenly and gradually as the radius of the curve increases. Discontinuities between adjacent blocks are avoided. In addition, the pitch of the wall is relatively constant for straight and curved portions of the wall. The wall leans back a slightly increased amount in concave portion and less in convex portions so that a relatively constant pitch is achieved throughout the entire serpentine wall. This uniform setback and relatively constant pitch enables more courses of blocks to be used in many serpentine walls, and helps produce a more stable serpentine wall where the combined weight of the wall and earth pressure remain within the footprint of the block.

[0023] A still further advantage of the present interlocking masonry wall block is that the integral projections allow the blocks forming one course to have a varying amount of lateral offset with relation to the course of blocks upon which they are stacked. The retaining wall can more easily avoid obstructions, such as a sump pump discharge pipe. The block can also be arranged to allow drain pipes to pass through the middle of the wall. This flexibility also allows one course of blocks to be laterally offset to accommodate the ledge or sill of a building. Thus, the present block facilitates the construction process and the ability to use the block in a wide variety of locations.

[0024] A still further advantage of the present interlocking masonry wall block is that the integral projections provide additional resistance to lateral side-to-side movement of the block. The blocks can easily be stacked so that one of the projections engages the inside surface of one of the side walls of a block beneath it. Accordingly, side-to-side movement is resisted not only by the adjacent blocks in the same course or tier, but by the blocks above and below it as well. Should one block in a given course shift or move out of abutting alignment with one of its adjacent blocks, then the remaining blocks in that row would still be held in place by the blocks above or below it. The projections are particularly helpful in holding the end blocks of the wall in place where the block would otherwise be free to slide laterally and out of place, or off the wall altogether.

[0025] A still further advantage of the present interlocking masonry wall block is that an entire serpentine wall can be built from a plurality of like-shaped blocks. The need for only a single block design results in reduced manufacturing, inventory, shipping and construction costs. The single block design also makes it easier to design a serpentine wall that is integrated to the shape of a specific and unique landscape setting.

[0026] A still further advantage of the present interlocking masonry wall block is its reduced weight. The open core design removes about thirty percent (30%) of the materials and weight of the block so that they are easier to handle during manufacture, shipping and construction. The open core design also reduces material costs which can be passed on to the consumer.

[0027] Other aspects and advantages of the invention will become apparent upon making reference to the specification, claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028]FIG. 1 is an elevated view of a house built to a unique landscape setting with a gradually sloping and contoured hill that feeds down to the level of the backyard patio of the house and a pre-existing tree.

[0029]FIG. 2 is an elevated view showing a three foot high serpentine retaining wall constructed from a plurality of the present like-shaped, interlocking masonry wall blocks, and integrated into the natural contours of the hill and unique landscape setting of the house.

[0030]FIG. 3a is a cross sectional view of FIG. 2 taken along line 3 a-3 a showing a straight wall section having a pitch of about Ps=5°.

[0031]FIG. 3b is a cross sectional view of FIG. 2 taken along line 3 b-3 b showing a high radius, convex curved portion of the wall having a pitch of about Phr=2°.

[0032]FIG. 3c is a cross sectional view of FIG. 2 taken along line 3 c-3 c showing a high radius, concave curved portion of the wall having a pitch of about Phr=9°.

[0033]FIG. 4 is an elevated, front perspective view of the interlocking masonry wall block showing the trapezoidal shape of the upper surface and open core of the block.

[0034]FIG. 5 is a lowered, front perspective view of the interlocking masonry wall block showing the trapezoidal shape of the lower surface, the open core of the block, and its rectangular shaped integral projections.

[0035]FIG. 6 is a front view of the interlocking masonry wall block.

[0036]FIG. 7 is a top view of the interlocking masonry wall block.

[0037]FIG. 8 is a bottom view of the interlocking masonry wall block showing the orientation of the offset projections relative to the inside surface of the front wall of the block.

[0038]FIG. 9 is a side view of the interlocking masonry wall block.

[0039]FIG. 10 is a top view of two courses of the present like-shaped interlocking blocks arranged in a straight configuration with the blocks in the upper course having an offset alignment to create an opening for a drain pipe, the blocks on the right being in about a full right alignment and the blocks on the left being in about a full left alignment.

[0040]FIG. 11 is a top view of two courses of the present like-shaped interlocking blocks arranged in a concave curve configuration that gradually increases from a low radius curve, through a medium radius curve, to a high radius curve.

[0041]FIG. 12 is a top view of two courses of the present like-shaped interlocking blocks arranged in a convex curve configuration that gradually increases from a low radius curve, through a medium radius curve, to a high radius curve.

[0042]FIG. 13 is a top view of a convex shaped retaining wall formed by the present like-shaped, interlocking masonry wall blocks, with a pitch of Ps=1 in the straight section, and about Pmr=0.7 in the medium radius section, and about Phr=0.4 in the high radius section.

[0043]FIG. 14 is a top view of a convex shaped retaining wall formed by a conventional rear flange, interlocking masonry wall blocks, with a pitch of Ps=1 in the straight section, and about Pmr=1.2 in the medium radius section, and about Phr=1.3 in the high radius section.

[0044]FIG. 15 is a top view of a concave shaped retaining wall formed by the present interlocking masonry wall blocks with a pitch of Ps=1 in the straight section, and about Pmr=1.4 in the medium radius section, and about Phr=1.8 in the high radius section.

[0045]FIG. 16 is a top view of a concave shaped retaining wall formed by a conventional, rear flange, interlocking masonry wall blocks with a pitch of Ps=1 in the straight section, and about Pmr=1.4 in the medium radius section, and about Phr=2.0 in high radius section.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0046] While this invention is susceptible of embodiments in many different forms, the drawings show and the specification describes in detail a preferred embodiment of the invention. It should be understood that the drawings and specification are to be considered an exemplification of the principles of the invention. They are not intended to limit the broad aspects of the invention to the embodiment illustrated.

[0047]FIG. 1 shows a house 10 with a walkout basement leading to a patio 12 constructed in the backyard of the house. The house 10 has a concrete foundation 14 which transitions to brick 16 along a sill 18 at the top of the foundation. The house is constructed into a hill 20 that levels off to a particular ground level 22 in the backyard of the house. The hill 20 and its terrain 30 and natural plant life 24 form a unique landscape setting 32 around the house 10.

[0048] The present invention relates to a masonry block 40 for constructing serpentine retaining walls with straight and curved portions, such as the landscape retaining wall 140 shown in FIG. 2. The serpentine wall 140 is easily integrated into a variety of landscape settings 32. The like-shaped blocks 40 have a setback, as discussed below. A degree of setback is maintained throughout the entire serpentine wall 140. As discussed below, the setback impacts the degree the wall is pitched or leans into the hill 20. As shown in FIG. 3a, 3 b and 3 c, the amount of pitch (P) in the wall 140 is somewhat less in convex curved portions of the wall and somewhat greater in concave portions of the wall relative to the pitch in straight portions of the wall.

[0049] An individual block 40 in accordance with the present invention is shown in FIGS. 4-9. The block 40 has a main body 42 with upper 44 and lower 45 surfaces. The upper 44 and lower 45 surfaces are generally parallel to each other. When laid in place on a horizontal supporting surface, the upper 44 and lower 45 surfaces are horizontal as well. The main body 42 includes a front wall 51, a rear wall 52, and opposed side walls 53 and 54. Each wall 51-54 is integrally formed to its two adjacent walls during the molding process. Each wall 51-54 has an inside 61 and an outside 62 surface. Each wall has a wall width of roughly two (2) inches between its inside 61 and outside 62 surfaces. The upper 44 and lower 45 surfaces of each wall 51-54 have a relatively smooth masonry finish. The walls 51-54 are solid and form continuous surfaces 44, 45, 61 and 62. The outer surface 62 of the front wall 51 is roughened to give it a natural cut or chipped stone finish. A conventional masonry material for landscape retaining wall blocks is used to form the block 40. A single block 40 weighs about twelve pounds.

[0050] The block 40 has a generally trapezoidal shape as best shown in FIGS. 7 and 8. The inside 61 and outside 62 surfaces of the front 51 and rear 52 walls are parallel, and perpendicular to the upper 44 and lower 45 surfaces. The inside 61 and outside 62 surfaces of the side walls 53 and 54 are also perpendicular or vertical to the upper 44 and lower 45 surfaces. The block 40 has a height of about four (4) inches and a depth of about eight (8) inches. The width of the block at its front wall 51 is roughly twelve (12) inches from the outer surface 62 of each side wall 53 and 54. The width of the block at its rear wall 52 is roughly ten (10) inches from the outer surface of each side wall 53 and 54. Each side wall 53 and 54, and its respective inside and outside surfaces 61 and 62, converge toward the other at an angle of about seven degrees (7°) as it extends toward the back wall 52. The outside surface 62 of the front wall 51 has beveled ends 65. The surface of these ends 65 angle back toward the rear of the block. The outside surface 62 of the angled ends 65 meet the outside surface of the side walls 53 or 54 along edges 67. The outside surface 62 of the rear wall 52 meets the outside surface of the side walls 53 or 54 along edges 68.

[0051] The block 40 has an open core or interior 80 that extends completely through the block from its upper surface 44 to its lower surface 45. The open core 80 is defined by the inside surfaces 61 of the front, rear and side walls 51-54. The open core 80 has a generally trapezoidal shape that is smaller in size and similar to the trapezoidal shape formed by the outer surface 62 or perimeter of the block 40. The open core 80 has a width at its front of about seven and a half (7½) inches, and a width at its rear of about six and a half (6½) inches. The open core 80 is about four (4) inches deep taken along a line perpendicular to the inside surfaces 61 of the front and rear walls 51 and 52. The comers 82 of the open core 80 are rounded to a radius of roughly three-quarters (¾) of an inch. One of ordinary skill in the art should readily appreciate that the volume of the core can vary, but is preferably maximized to decrease the weight and material cost of the block without impairing the strength, integrity and manufacturability of the block. Similarly, the actual shape and dimensions of the core 80 can vary, provided the core maintains its ability to receive the lug-shaped projections of another block 40, as discussed below. The open core 80 should not contain any obstruction that would interfere with the desired ability to receive these lugs.

[0052] Two integral lug-shaped projections 100 and 101 extend from the lower surface 45 of the block 40. The projections 100 and 101 have front 111, rear 112 and opposed side 113 and 114 surfaces. These surfaces are generally flat and perpendicular to the lower surface 45 of the block and parallel to the inside and outside surfaces 61 and 62 of the walls 51-54, respectively. Each lug 100 and 101 has a bottom surface 115 that is generally parallel to the lower surface 45 of the block 40. Each lug 100 and 101 has a width of about one (1) inch from side 113 to side 114, and a length or thickness of about one and a half (1½) inches from front 111 to rear 112. Each lug 100 and 101 has a height of about five-eighths (⅝) of an inch, and its comers and vertical edges 117 are rounded to a radius of about seven-sixteenths ({fraction (7/16)}) of an inch. One of ordinary skill in the art should readily appreciate that the size and shape of the lugs 100 and 101 can vary provided they maintain their strength, integrity and manufacturability.

[0053] Each projection 100 and 101 is generally centered between the inside 61 and outside 62 surfaces of its respective side wall 53 or 54. Each projection 100 and 101 has a portion 118 positioned forward or in front of the inside surface 62 of the front wall 51. This portion 118 provides an amount of setback 120 for the block 40. The perpendicular distance between the front surface 111 of each projection 100 and 101 and the inside surface 62 of front wall 51 is the setback dimension 120. In this embodiment, the setback dimension 120 is shown to be about one-quarter (¼) of an inch. The setback 120 is the same for both projections 100 and 101. However, it should be understood that the setback dimension 120 could be larger or smaller without departing from the broad aspect of this present wall block invention. Each projection 100 and 101 has a centerline 119. This centerline 119 is shown perpendicular to the inside and outside surfaces 61 and 62 of the front wall 51, but could be parallel to the inside and outside surfaces of its respective side wall 53 or 54.

[0054] The like-shaped blocks 40 are structured to be laterally aligned in an abutting side-by-side engagement, and vertically aligned in a staggered, stacked manner so that one block rests atop two other blocks. When arranged in this manner, the blocks 40 form a multi-tiered wall 140, such as the wall shown in FIG. 2. The wall 140 is typically constructed one course at a time. Once a lower course 141 is set in place, an upper course 142 is placed on top of it. The blocks 40 can be arranged to form walls 140 having straight wall portions 150 as in FIG. 10, concave curved wall portions 160 as in FIG. 11, and convex curved wall portions 170 as in FIG. 12. The concave portions 160 have a degree of curvature that ranges from a low radius curve 161, to a medium radius curve 162, to a high radius curve 163. Similarly, the convex portions 170 range from low 171, to medium 172, to high 173 radius curves. The blocks 40 can be arranged to gradually or rapidly increase or decrease the radius of the curvature of the concave or convex curves 160 or 170, which enables the wall 140 to conform to the unique landscape setting 30.

[0055] When erecting a wall 140, a gravel or sand bed 179 is preferably formed to level the terrain 32 where the first course 141 of blocks 40 is to be laid. In each course 141 or 142, the front and rear side edges 67 and 68 of laterally adjacent blocks 40 are aligned. The front edges 67 are aligned in abutting engagement in straight wall portions 150 as shown in FIGS. 2 and 13, low radius concave wall portions 161 as shown in FIGS. 11 and 15, and all convex wall portions 170-173 as shown in FIGS. 12 and 13. The front and rear edges 67 and 68, as well as the entire outside surfaces 62 of side walls 53 or 54 of adjacent blocks 40 are flushly aligned in abutting engagement for a medium radius concave wall portions 162 as shown in FIG. 11. High radius concave wall portions 163 are formed by aligning the rear edges 68 of adjacent blocks 40 as shown in FIG. 11. The lower surface 45 of each block 40 in the first or lowest course 141 is placed at the same horizontal level, which is deemed the ground level 22. In the first course 141, the projections 100 and 101 can extend into the gravel or sand bed 179. The upper surfaces 44 of the blocks 40 forming the lower course 141 form a generally horizontal platform upon which the upper course 142 can be stacked. The lower surface 45 of each block 40 in each stacked, upper course 142 is placed on and rests on the upper surfaces 44 of the blocks in the lower course 141 upon which it is placed.

[0056] An interlocking fit is achieved between the like-shaped blocks 40 in adjacent upper 142 and lower 141 courses. Each block 40 in the upper course 142 is laid in a staggered manner relative to the lower course 141 so that the upper block is placed atop two lower blocks. Each block 40 in the upper course 142 is placed so that one of its lug-shaped projections 100 ort 101 extends into and is received by the open core 80 of one of the lower blocks. The other projection 100 or 101 extends into and is received by the open core 80 of an adjacent lower block. The front surface 111 of each lug 100 and 101 of the upper block 40 abuts the inside surface 61 of the front wall 51 of its respective lower block. This abutting engagement between the upper and lower blocks 40 in adjacent courses 141 and 142 forms the interlock that prevents the block in the upper course 142 from moving forward. This interlock enables the blocks 40 in the upper courses 142 to resist the pressure of the earth and hill 20 behind the wall 140.

[0057] A further aspect of the interlocking fit is achieved by aligning the block 40 in the upper course 142 so that one of its projections 100 or 101 abuts the rounded comer 82 or inside surface 61 of the side wall 53 or 54 of the block in the lower course 141. When in a full right 181 or full left 182 alignment as shown in FIG. 10, the blocks 40 in the upper course 142 are prevented from sliding sideways or laterally relative to the blocks in the lower course 141. The block 40 in the lower course 141 experiences a similar resistance to movement in the opposite lateral direction. A block in a middle course may experience a resistance to both right and left movement.

[0058] Adjacent blocks 40 in a particular course 141 or 142 can also be arranged in an offset alignment 185. One block 40 can be positioned in a fall right alignment 181 and its adjacent block can be position in a full left alignment 182 to form a gap or opening 187 between the two blocks shown as in FIGS. 2 and 10. The maximum amount of offset of the preferred embodiment of the block 40 is about six (6) inches. The ability to laterally offset adjacent blocks 40 to create openings 187 in the otherwise solid wall 140 enables the wall to accommodate drainage pipes, gutter down spouts, sump pump piping or other obstacles, and helps prevent excessive water building up behind the retaining wall.

[0059] As discussed above, the projections 100 and 101 produce an amount of setback 120 between the upper and lower courses of blocks 141 and 142. When the wall 140 is properly constructed, the blocks 40 in the upper course 142 are set back a predetermined amount 120 from the blocks on which they are placed. In the preferred embodiment, the outer surface 62 of the front wall 51 of the upper block 40 is set back about one quarter (¼) inch from the outer surface of the lower blocks on which it is placed. The setback dimension 120 directly affects the amount or degree of pitch P in the wall 140. The setback 120 of each block 40 in the upper course 172 is substantially the same when measured along the centerline 119 of each projection 100 or 101. When the blocks 40 form a straight wall segment 150, the height of the blocks 40 and the setback amount 120 determine the pitch of the wall. The amount of pitch can vary slightly in an actual construction setting due to the present of dirt or other debris, which can come between the lugs 100 and 101 of the upper block and the inside surface 61 of the front wall 51 of the lower block. When the blocks 40 form a curved wall segment 160 or 170, the pitch of the wall varies. For example, as shown in FIG. 13, a wall 140 having a pitch in straight wall section of Ps=1.0, should have a reduced pitch in a medium radius convex section 172 of about Pmr=0.7 times Ps, and a high radius convex section 173 of about Phr=0.4 times Ps. As shown in FIG. 15, the wall 140 should have an increased pitch in a medium radius concave section 162 of about Pmr=1.4 times Ps, and a high radius concave section 163 of about Phr=1.8 times Ps. A more consistent pitch is believed to occur with this wall 140 than in other conventional walls, such as the wall shown in FIGS. 14 and 16, because the lug-shaped projections 100 and 101 do not span the entire width of the block 40, and are located toward the front wall 51 and inwardly from the outside surfaces 62 of the side walls 53 and 54.

[0060] The top course of blocks 40 in the landscape retaining wall 140 is preferably capped by cap stones 195 to cover the open cores 80 of the blocks 40 that form the top course or portion of a course. These cap stones 195 provide a finished look to the wall. These cap stones 195 can be glued or otherwise adhered to the upper surface 44 of the blocks 40.

[0061] While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the broader aspects of the invention. 

I claim:
 1. A masonry wall block for stacking atop other like-shaped blocks, the masonry wall block comprising: a main body having a front wall, a rear wall and first and second side walls, each of said walls having inside and outside surfaces and upper and lower surfaces, said inside surfaces of said walls forming an open core, said upper surfaces of said walls forming an upper surface of said main body, and said lower surfaces of said walls forming a lower surface of said main body, said upper and lower surfaces of said main body being substantially parallel; first and second spaced apart, projections extending from said lower surface of said main body, said first projection extending from said lower surface of said first side wall and said second projection extending from said lower surface of said second side wall, each of said projections being located on opposite sides of said open core, and each of said projections having a portion with a front surface located between said inside and outside surfaces of said front wall to define a setback dimension; and, wherein said block is adapted to be stacked in a staggered relationship atop first and second lower like-shaped blocks, said first projection of said block being received by said open core of said first lower like-shaped block, and said second projection of said block being received by said open core of said second lower like-shaped block, said front surface of each of said projections of said block being adapted to abuttingly engage said inside surface of said front wall of its respective lower like-shaped block, and said block being positioned rearwardly of said lower like-shaped blocks an amount equal to said setback dimension when in said abutting engagement with said lower like-shaped blocks.
 2. The masonry wall block of claim 1, and wherein each of said projections has a second portion with a rear surface located between said inner surfaces of said front and rear walls, each of said projections having a thickness dimension greater then its said setback dimension.
 3. The masonry wall block of claim 2 and wherein said setback dimension is less than half said thickness dimension.
 4. The masonry wall block of claim 1 and wherein said abutting engagement forms an interlock between said block and the first and second lower like-shape block, said interlock preventing said block from being pushed forward relative to said lower like-shaped blocks.
 5. The masonry wall block of claim 1, and wherein said block has a predetermined width dimension between said outside surfaces of said first and second side walls, said open core has a predetermined width dimension between said inside surfaces of said first and second side walls, and each of said projections has opposed side surfaces and a predetermined width dimension between said opposed side surfaces, and wherein said width dimension of each of said projections is less than one tenth of said width dimension of said block, and said width dimension of said open core is at least half said width dimension of said block, and wherein said block is able to be staggered various amounts atop said lower like-shaped blocks.
 6. The masonry wall block of claim 5 and wherein said width dimension of each of said projections is about one seventh that of said width dimension of said open core.
 7. The masonry wall block of claim 5 and wherein said like-shaped blocks are adapted to be offset to form a gap between said side walls of said like-shaped blocks.
 8. The masonry wall block of claim 1, and wherein said inside and outside surfaces of said front, rear and opposed side walls are substantially perpendicular to said upper and lower surfaces.
 9. The masonry wall block of claim 8, and wherein said inside and outside surfaces of said front wall are substantially parallel, said inside and outside surfaces of said rear wall are sustantially parallel, said inside and outside surfaces of said first side wall are substantially parallel, and said inside and outside surfaces of said second side wall are substantially parallel.
 10. The masonry wall block of claim 9, and wherein said front surface of each of said projections is substantially parallel to said inner surface of said front wall.
 11. The masonry wall block of claim 1, and wherein said block is adapted for use with a plurality of other like-shaped blocks to form a multi-course wall having a serpentine shape with gradually increasing curved portions. 